A population of 50 adult and 20 pediatric patients with moderate to severe hypertension will be recruited. A complete ophthalmologic evaluation including fundus photography and fluorescein anigography will be performed. The hypertensive retinopathy will be classified based upon a new scheme developed by the investigators. Over the next four years, the retinopathy will be reclassified every four months. The success of antihypertensive therapy and any cerebrovascular, cardiovascular, or renovascular complications will be recorded. In this manner it will be possible to correlate changes observed in the fundus with the initial level of hypertension and the success of the antihypertensive therapy. We will also attempt to correlate the complications of the hypertension (cerebral, cardiac, or renal) with the patient's initial retinopathy and the subsequent course of the retinopathy. Other studies to be done will include use of a television ophthalmoscopy system to record retinal flow rates, transit times and oximetry data on hypertensive patients before and after antihypertensive therapy.